References to America’s past “hegemony” are perplexing. How can one reconcile that characterization with the “loss” of China, the stalemate in the Korean War, the Soviet invasion of Czechoslovakia, the fall of Saigon and the ascension of Ayatollah Ruhollah Khomeini, to name only a few strategic setbacks?

The first responder reflex often nurtures unreasonable expectations and discourages allies from playing a more active role.

In truth, U.S. influence has always been but one of an infinite number of phenomena that shape the day’s events. The Scottish historian Denis Brogan made this point forcefully in 1952, advising Americans to reject the belief that affairs beyond their shores head in unfavorable directions “only because some elected or non-elected Americans are fools or knaves.” U.S. foreign policy deserves solid marks if it succeeds in managing challenges abroad and minimizing their impact; few crises, after all, lend themselves to total resolution.

It is unclear what President Obama could have done to prevent Russia’s advances in Crimea (and similarly unclear what his predecessor could have done to forestall its invasion of Georgia). What matters now are the steps that the U.S. and Western Europe take to nurture a peaceful and prosperous Ukraine without provoking a new confrontation. It is not the failure to prevent crises that reflects weakness, but invoking “realism” to justify continued inaction in their aftermath.

Temperament also matters on the global stage. While certain events may merit a rapid and forceful response, others call for restraint. The greater the stakes, in fact, the more policymakers must allow themselves time to deliberate the full array of responses. During the Cuban Missile Crisis, careful judgment allowed President John F. Kennedy to avoid a nuclear exchange with the Soviet Union without accepting the presence of its missiles in Cuba. And, as the nearly-50-year effort to contain Soviet expansionism demonstrated, discipline that serves a strategic vision can produce dramatic results.

As developments unfold in Ukraine, it bears repeating that the U.S. does not necessarily demonstrate leadership by trying to be the first responder whenever fires break out; in fact, that reflex nurtures unreasonable expectations and discourages allies from playing a more active role. Given the frailty of its economic recovery, the U.S. should articulate more stringent criteria for determining if a given crisis threatens its vital national interests. Should it proceed from impulse instead of analysis, its foreign policy risks devolving into constant crisis-management mode. If, instead, it continues working with longstanding allies and emerging powers to strengthen today’s liberal international system, it may be able to constrain the scope of future malfeasance without eroding its leadership.